1. Field of the Invention
The present invention relates to a method of forming and maintaining an artificial snow layer, and more particularly a method of forming and maintaining an artificial snow layer at e.g. an artificial snow indoor skiing slope.
2. Description of the Related Art
Conventional methods of forming an artificial snow layer will be described. According to a first conventional method, indoor atmosphere present immediately above a floor surface is refrigerated to e.g. a low temperature ranging between -6 and -10 degrees in Celsius and then cold water is sprayed through a spraying nozzle onto the floor with compressed air. With this, through the adiabatic expansion effect associated with the nozzle spraying and the refrigeration of the indoor air, the sprayed water is frozen into fine ice particles. Then, as the ice particles are accumulated on and spread over the floor, an artificial snow layer comprised of ice particles is formed on the floor surface.
According to a second conventional method, water-absorbent resin particles containing water are sprayed over a floor surface and the layer of the sprayed water-containing resin particles is frozen there by means of a refrigerating means incorporated at the floor. Then, this frozen layer is pulverized into fine particles by a pulverizing machine, thereby to form on the floor surface an artificial snow layer comprising the layer of frozen water-absorbent resin particles. This method is described, for instance, in the PCT/AU85/00267.
However, according to the first conventional method, an enormous amount of energy is required for maintaining the indoor atmosphere (the atmosphere can be huge in volume in case of e.g. the indoor skiing slope) at such low temperature ranging between -6 and -10 degrees in Celsius regardless of the outdoor temperature. The amount of energy required will be significant in the summer season. Therefore, this method suffers the problem of significant cost for the formation of the artificial snow layer. Moreover, the maintenance costs will also be significant for maintaining the indoor atmosphere at the low temperature of -2 to -3 degrees in Celsius by preventing the snow layer from being melted.
In addition, since the indoor atmosphere is maintained at such low temperature as described above during the snow-layer forming operation and also during the actual use of the formed snow layer, the user of the slope, i.e. a skier, or a worker tends to feel uncomfortably cold or even feel dizzy due to a thermal shock from the drastic change in the temperature between the extremely low indoor atmosphere and the warm or hot (may exceed 30 degrees in Celsius in summer) outdoor atmosphere when he/she comes in and out of the construction. Thus, this method may cause the problems of health hazard and discomfort for the users and workers as well.
On the other hand, according to the second conventional method, the artificial snow layer consists of a great number of water-absorbent resin particles. Then, although the layer is pulverized into fine particles, the layer consisting of the pulverized particles still gives a considerably different skiing feel to the users than they get from natural snow.